Checking your balance is a “constant” method, (as you can see from the ABI) which means it reads from the blockchain and costs no gas to execute.

Transferring a balance, however, changes the state of the blockchain and requires a small gas payment. In the next command the "{from:YOURADDR}" parameter provides that payment. You can specify gas explicitly like this: "{from:YOURADDR,gas:2500000}" but geth has a default it will provide if you don't which is why I don't show it below. (Unused gas is always refunded.)

BUT FIRST! We need the exchange address to send it to. In Poloniex, it’s under "Balances" and "Deposits and Withdrawals". Find DAO in the list and click the link to get a deposit address.

Now here’s the transfer execution command (This will transfer 2000 DAO tokens to a polo address from my second ETH account):